Snake

This is a Ninja AU where assassins can use ninjutsu and such. Nagisa has been the world's third most dangerous assassin since he was eight and is the best of his father's three companies: SIB, SAC, and SNA. Read to find out what they are and how a smart assassin has yet to kill his teacher and ended up in E-Class when he's too smart for it. Karmagisa because they're dating.